Automatic fuse-plug.



L. M. BOWMAN. AUTOMATIC FUSE PLUG. APPLICATION FILED AUG. 26, 1913.

Patented May 19, 1914 Fort Worth, in the county of Tarrant and construction,

-a hollow base, an arcuate fuse o vtioned within said base and'adapted to sup UNITED STATES PATENT OFFICE.

LEVI 141. BOWMAN, or FORT FARMER,

WORTH, TEXAS, ASSIGNQR OF ONE-HALF '10 WILLIAM C.

O]? TULSA, OKLAHOMA.

auroiaaric rusarmrc.

, Specification 0t Letters Patent. Application filed August 26, 1918. Serial No. 786,795.

rammed May 19, 1914.

To all who/nit may concern:

Be it known that I,"Lnvr M. BOWMAN, a

citizen of the United States, residing at State of .Texas, have invented certain new and useful Improvements in Automatic Fuse-Plugs; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same. This invention comprehcnds improvements in automatic fuse plugs, and relates more -particularly wherein a plurality of fuse wires are provided, which are adapted to be successively engaged by a swinging contact arm.

One of the objects of the invention is to construct an, automatic fuse'plu of this type,. which shall be of extreme ysimple cheap to manufacture, and of the same shape as the plugs now in common use, so that t maybe used in.the ordinary plug sockets.

Another and more specific ob'ect of the invention is to provide a fuse having 1 er posi:

port a plurality of' fuse wires, a'swinging arm which successively engages the fuse fro onewire to the preceding one when said rst mentioned wire is fused, and means determined number of wires have been fused, so that should a permanent short circuit occur, all of the fuse tion proceeds,

wires will not be broken.

With these and other objects in view, as

will become more apparent as the descrip nation and arrangement of parts, asfwfll be hereinafter fully described and claimed.

For a complete understanding of my invention, reference is to be had to the following description and accompanying drawto those of the type projecting flanges for locking the arm against movementafter a certain pre-- the invention consists in certam novel features of construction, combi:

In the preferred embodiment of my in vention, I provide a preferably porcelain base, generally. designated 5 which is hol- 1 w and which tapers at its inner end so as to fit within a common plug socket. A cover 6 is employed for closing the base, and a metalsleeve, or casin 7 extends around the central portion of the base, and is threaded for engagement with the interior of'a plug socket. An arcuate fuse holder 8, formed of'solne conducting material, such as brass, is positioned within the hollow-base and is provided, adjacent its upper and lower edges, with the inwardly 9. The holder is in the form of a. plate making an arc of about 321 degrees, or nine-tenths of a perfect circle.

A plurality of fuse wires 11 are secured at their ends to the flanges 9 and are disposed in parallel relation with respect to one another.

A sleeve member 12 extends centrally through the base,and has acontact portion 13 formed upon the inner end thereof. The sleeve .member extends through an opening 14 formed in the near wall of the base 5, and the'contact portion 13 seats in the annular recess 15. A preferably mica disk 16 rests upon the shoulder 17 formed in the outer edge of the base and serves as a sup rt for the outer end-of the sleeve 12, as 0 early shown in the drawings.

A stem 18, having a push button 19, which is preferably formed of hard rubber, secured to 'the outer end thereof, extends through central openings formed in thecover 6, and disk 16, into the sleeve 12. A contact arm 20 is rigidly secured to the stem 18 and extends at right angles thereto, the free end of the arm being forked for engagement with the fuse wires. The sleeve 12 is formed with anarcuate slot 21, forming an arc of the same number of degrees as the fuse holder 8, and the contact arm works through this slot. An expansive spring 22 is secured at one end of'the stem 18 and at its other end to the inner endof thesleevc 12 and serves to force the stem outwardly and, also impart. a rotational movement thereto.

In order to automatically lock the arm 20 after a predetermined number of fuss wires have been broken, I provide the outer wall of the slot 21, with a plurality of radially extending grooves 23, into which the arm 20 9 13 of the sleeve. \Vhen a wire is fused from any cause whatsoever,- the spring 22 swings the arm 20 to the next preceding fuse wire, and therefore the break in the circuit is only momentary. In case of a continuous short circuit, a plurality of fuse wires ,will be destroyed, depending upon the distance of the arm 20 from a groove 23. As soon as the arm reaehesone of these grooves, it seats therein and is thereby checked against further movement until it is unseated from said groove by an inward push upon the stem 18 This automatic leek feature-forms a very important part of the improved plug since it prevents all of the fuse wires being destroyed whenever a permanent short circuit occurs 7 From the foregoing description taken in connection with the accompanying drawings, it will be apparent that -I have provided a very simple, practical and economical automatic fuse plug, which may be used in the fuse sockets now commonly employed and which is equal too. large number of the ordinary fuse plugs, which -are provided with only one fuse arc.

IVhile I have shown preferredembodiment of-my invention, it will be understood that minor changes in construction and arrangement of parts may be made without departing. from the scope and spirit of the invention as claimed.

.Having thus described my invention, I

claim 1. 'In an automatic fuse plug, the combination of a plurality of fuse wires, contact' means engaging one of said wires, means for moving said contact means into engagement with the other fuse wires, and. means for automatically locking the contact means against movement after a predetermined -.numl)er of fuse wires have been-destroyed;

"QQIn an'automatie fuse plug, the combination of a plurality of fuse wires contact means engaging one of said wires, spring means for moving said'contact means into engagement with the other of said'wir'es, and means for automatically locking the contact means against movement after a and described the 'stroyed.

predetermined number of fuse wires have been destroyed.

3. In an automatic fuse plug, the combination of an arcuate fuse wire holder, plurality of fuse wires connected to said holder, a rod extending axiall" through the holder, a contact arm rigidly secured to said rod, means for rotating the rod whereby the contact arm will successively engage the fuse wires and means for automatically locking the arm against movement after a predetermined number of fuse wires have been destroyed.

4. In an automatic fuse plug, the combination of an arcuate fuse wire holder, fuse wires extending across said holder in parallel relation to one another, a sleevemember extending axially through the holder, a stem mounted for longitudinal and rotational movement within the sleeve member, said sleeve member being formed with an arouate slot, :1 contact arm connected to the stem and extending through the slot for successive engagement with the'fuse wires, means for rotating the stem in one direction and means for automatically locking the stem against movement after a predetermined number of fuse wires have been destroyed.

"5. In an automatic fuse plug, the combination of an are'uate fuse wire holder, a plurality of fuse wires' stretched across said holder, a sleeve extending axially through the holder and formed with an arcuate slot, one wall of the slot being formed with radial grooves, a push rod positioned within the sleeve member, a contact arm connected .to the push rod and working through said slot for excessive engagement with the'fuse wires and means for rotating-the arm and forcing the same toward the grooved wall of the slot, said grooves causing the arm to beheld against movement after a predetermined number of wires have been dev6. In an automatic fuse plug, the combination ofa plurality of fuse wires, Contact means engaging .one of said-wires, means for moving said contact means into engagement with the other of said fuse wires, means for automatically locking the contact' means against movement; after a predetermined number of fuse wires have been destroyed,

and ,ineans for'releasing the contactmeans from the automatic locking means.

In testimony whereof Iafiix my signature in presence of two'witnesses.

LEVI M.- BOlVMAN.

Copie's of, this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, D. C." w 

